A system and a method for acquiring a moving image are provided. The system includes an image capturing unit capturing two images having different exposure times at a predetermined time slot, an image storing unit storing at least one of two images which were captured at a time slot previous to the predetermined time slot and which have different exposure times, an output image generating unit generating an output image by synthesizing the two images captured at the predetermined time slot or by synthesizing any one of the two images captured at the predetermined time slot and any one of the two images captured and stored at the previous time slot, an exposure time calculating unit receiving the images captured at the predetermined time slot and setting exposure times for a next time slot, and an exposure time storing unit storing the exposure times for the next time slot.